”Turn it off!” one man shouted when the Coca-Cola spot opened for Born on the Fourth of July on a recent Saturday night in Manhattan. Audience hisses followed, as three little boys in a treehouse bemoaned the fact that they had climbed all the way up to their hangout but, alas, had forgotten to bring the Coke Classic. ”Michael” will get it, the boys figure, and none other than Michael Jordan comes hurtling across the yard with a six-pack and, in glorious but predictable slo-mo, flies up to the treehouse and slam-dunks the fizz. ”Two points!” another guy in the audience yelled approvingly, though heckles continued as if there’d been a hairball on the lens.

Almost anyone who has been in a movie theater lately has learned to sit through an ad or two before the show starts. But with a wave of its wand, the Magic Kingdom is trying to banish such screen-selling to Never-Never Land. The Walt Disney Co. announced last month that it would no longer allow any of its Disney, Hollywood Pictures, or Touchstone movies to run with commercials. ”We’ve been hearing hissing and boos for years, and it became obvious to all of us that four or five minutes of ads was becoming a turnoff,” says Richard Cook, president of Disney’s Buena Vista Pictures distribution arm. ”It’s not conducive to the moviegoing experience.”

Commercials are now shown regularly at about one-third of the country’s 23,000 movie screens. Kodak, Oldsmobile, Puma, Dr Pepper, Christian Dior, the U.S. Marines, even ABC-TV — they’ve all done it at the movies. Their approach varies from the predictable brand-brandishing hard sell you see on TV to the truly enjoyable pitch that you’d almost pay to see, like the Michael Jackson claymation extravaganza for California raisins (which later did turn up on TV). Cinema ads are extremely lucrative to theater owners; only popcorn is more profitable. Advertisers love them because they reach a captive audience that can’t zap them away. And, until now, most Hollywood studios — many of which own, in full or in part, sizable theater chains — have given on-screen ads the go-for-it nod.

But Disney’s decision has thrown the cozy arrangements off balance. The Walt Disney Co. has major clout, and its edict has put pressure on theaters and other studios not to look like money changers in these temples of culture. Rob Friedman, head of advertising and publicity for Warner Bros., which as a policy prohibits on-screen ads but hasn’t always been terribly insistent, says, ”We feel the same way as Disney, and I’m sure we’ll be enforcing (the contractual agreement) more stringently.” Columbia Pictures’ reaction is more typical. ”We have not taken the Disney stand,” says a spokesman. ”We’re just monitoring the situation very carefully.” Other studios refused to comment.

Still, the industry is buzzing about Disney’s ulterior motives: Is the theaterless titan trying to cut out the profits of its rivals? Is Disney’s holier-than-thou attitude really aimed at Universal, which has been running theater ads for its Universal Studios Florida tour, an amusement center that will go head-to-head with Disney World when it opens in May? ”Disney’s playing hardball, trying to short-circuit the competition,” says Michael Kaminer, spokesman for Screenvision, the largest broker of screen advertising.

”Hard as it may be to believe, our motives are pure,” says Disney’s Cook. ”It’s not about any particular commercial or the quality of the commercials. It’s about our feeling that it was really an insult to the patron, who is not going out to experience the mundane. And it’s not about money — except in that we don’t want to see an erosion of the moviegoing audience. The home-movie experience, with larger screens and stereo sound, is coming closer and closer to what you have in a theater. Any time you make the theatrical experience so much like what people can get at home, you put the industry in danger.” Disney, he says, doesn’t allow ads on videos of its films either.

So, how did all this nasty business start, anyway? Cinema business folk tend to justify their trade with history. Film ads began to pop up shortly after Thomas Edison invented the vitascope, an early film projector, in 1896, says Cineplex Odeon spokeswoman Jo Mira Clodman. ”Many stars, like Greta Garbo, got their start in on-screen ads.” A variety of ads played regularly at theaters until the 1950s, when sponsors left the movies for the then-better economics of the new medium, television. Fittingly, during the last decade, as networks began to lose millions of viewers, advertisers rediscovered the big screen. And all along, movie ads have actually been popular in Europe and Australia, where 15 minutes of pre-film soft sell is not unusual.

But the Disney ban — which goes into effect March 23 with the Touchstone release of Pretty Woman — leaves theaters and the ad brokers who serve them oddly incapable of uttering the C-word. United Artists Theaters, the largest chain in the U.S. (not owned by UA, the studio), is showing the Michael Jordan/Coca-Cola spot on its more than 2,600 screens, and a spokesman says, ”We view it not as a commercial but as a concession trailer.”

Screenvision, the largest cinema-ad broker, with commercials on 6,050 screens, has everything to lose if other studios follow suit. ”We agree with Richard Cook — commercials don’t belong on movie screens,” Screenvision chairman/CEO Terry Laughren said in a statement. ”That’s why we run entertaining mini-movies at least 60 seconds long…”